Phlebotonics for venous insufficiency

BACKGROUND

Chronic venous insufficiency (CVI) is a condition in which veins are unable to transport blood unidirectionally towards the heart. CVI usually occurs in the lower limbs. It might result in considerable discomfort, with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is the second update of a review first published in 2005.

OBJECTIVES

To assess the efficacy and safety of phlebotonics administered orally or topically for treatment of signs and symptoms of lower extremity CVI.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and Clinicaltrials.gov trials register up to 12 November 2019. We searched the reference lists of the articles retrieved by electronic searches for additional citations. We also contacted authors of unpublished studies.

SELECTION CRITERIA

We included randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of phlebotonics (rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, French maritime pine bark extract, grape seed extract and aminaftone) in patients with CVI at any stage of the disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardized mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence intervals (CIs) and percentage of heterogeneity (I²). Outcomes of interest were oedema, quality of life (QoL), assessment of CVI and adverse events. We used GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

We identified three new studies for this update. In total, 69 RCTs of oral phlebotonics were included, but only 56 studies (7690 participants, mean age 50 years) provided quantifiable data for the efficacy analysis. These studies used different phlebotonics (28 on rutosides, 11 on hidrosmine and diosmine, 10 on calcium dobesilate, two on Centella asiatica, two on aminaftone, two on French maritime pine bark extract and one on grape seed extract). No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Moderate-certainty evidence suggests that phlebotonics probably reduce oedema slightly in the lower legs, compared with placebo (RR 0.70, 95% CI 0.63 to 0.78; 13 studies; 1245 participants); and probably reduce ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; 15 studies; 2010 participants). Moderate-certainty evidence shows that phlebotonics probably make little or no difference in QoL compared with placebo (SMD -0.06, 95% CI -0.22 to 0.10; five studies; 1639 participants); and similarly, may have little or no effect on ulcer healing (RR 0.94, 95% CI 0.79 to 1.13; six studies; 461 participants; low-certainty evidence). Thirty-seven studies reported on adverse events. Pooled data suggest that phlebotonics probably increase adverse events slightly, compared to placebo (RR 1.14, 95% CI 1.02 to 1.27; 37 studies; 5789 participants; moderate-certainty evidence). Gastrointestinal disorders were the most frequently reported adverse events. We downgraded our certainty in the evidence from 'high' to 'moderate' because of risk of bias concerns, and further to 'low' because of imprecision.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that phlebotonics probably reduce oedema slightly, compared to placebo; moderate-certainty evidence of little or no difference in QoL; and low-certainty evidence that these drugs do not influence ulcer healing. Moderate-certainty evidence suggests that phlebotonics are probably associated with a higher risk of adverse events than placebo. Studies included in this systematic review provided only short-term safety data; therefore, the medium- and long-term safety of phlebotonics could not be estimated. Findings for specific groups of phlebotonics are limited due to small study numbers and heterogeneous results. Additional high-quality RCTs focusing on clinically important outcomes are needed to improve the evidence base.

Paroven and Graduated Compression Hosiery for Superficial Venous Insufficiency

The effects of Sigvaris graduated compression hosiery and Paroven on symptoms of superficial venous insufficiency were assessed in a prospective, randomized, crossover study. Seventy-two patients awaiting surgery for non-cosmetic symptoms associated with varicose veins received 4-week treatments in random order, namely; placebo, Paroven alone, Sigvaris graduated compression hosiery and placebo, Sigvaris graduated compression hosiery and Paroven. Symptoms were assessed before and after each treatment using linear analogue scales. No statistically significant effects were observed, but there was a consistent trend for both Paroven alone and hosiery alone to produce modest improvements in symptoms. The relief of symptoms associated with a combination of Paroven and Sigvaris graduated compression hosiery was greater than that produced by either treatment on its own.

Phlebotonics for venous insufficiency

BACKGROUND

Chronic venous insufficiency (CVI) is a common condition caused by valvular dysfunction with or without associated obstruction, usually in the lower limbs. It might result in considerable discomfort with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is an update of a review first published in 2005.

OBJECTIVES

To assess the efficacy and safety of phlebotonics administered both orally and topically for treatment of signs and symptoms of lower extremity CVI.

SEARCH METHODS

For this update, the Cochrane Vascular Trials Search Co-ordinator (TSC) searched the Specialised Register (August 2015), as well as the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7). The reference lists of the articles retrieved by electronic searches were searched for additional citations. We also contacted pharmaceutical companies and searched the World Health Organization (WHO) International Clinical Trials Registry Platform Search Portal for ongoing studies (last searched in August 2015).

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract and aminaftone in patients with CVI at any stage of the disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardised mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence interval (CIs) and percentage of heterogeneity (I(2)). Additionally, we performed sensitivity analyses.

MAIN RESULTS

We included 66 RCTs of oral phlebotonics, but only 53 trials provided quantifiable data (involving 6013 participants; mean age 50 years) for the efficacy analysis: 28 for rutosides, 10 hidrosmine and diosmine, nine calcium dobesilate, two Centella asiatica, two aminaftone, two french maritime pine bark extract and one grape seed extract. No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria.Moderate-quality evidence suggests that phlebotonics reduced oedema in the lower legs compared with placebo. Phlebotonics showed beneficial effects among participants including reduced oedema (RR 0.70, 95% CI 0.63 to 0.78; I(2) = 20%; 1245 participants) and ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; I(2) = 47%; 2010 participants). Low-quality evidence reveals no difference in the proportion of ulcers cured with phlebotonics compared with placebo (RR 0.94, 95% CI 0.79 to 1.13; I(2) = 5%; 461 participants). In addition, phlebotonics showed greater efficacy for trophic disorders, cramps, restless legs, swelling and paraesthesia, when compared with placebo. We identified heterogeneity for the variables of pain, itching, heaviness, quality of life and global assessment by participants. For quality of life, it was not possible to pool the studies because heterogeneity was high. However, high-quality evidence suggests no differences in quality of life for calcium dobesilate compared with placebo (MD -0.60, 95% CI -2.15 to 0.95; I(2) = 40%; 617 participants), and low-quality evidence indicates that in the aminaftone group, quality of life was improved over that reported in the placebo group (MD -10.00, 95% CI -17.01 to - 2.99; 79 participants). Moderate-quality evidence shows that the phlebotonics group had greater risk of non-severe adverse events than the placebo group (RR 1.21, 95% CI 1.05 to 1.41; I(2) = 0; 3975 participants). Gastrointestinal disorders were the most frequently reported adverse events.

AUTHORS' CONCLUSIONS

Moderate-quality evidence shows that phlebotonics may have beneficial effects on oedema and on some signs and symptoms related to CVI such as trophic disorders, cramps, restless legs, swelling and paraesthesia when compared with placebo but can produce more adverse effects. Phlebotonics showed no differences compared with placebo in ulcer healing. Additional high-quality RCTs focused on clinically important outcomes are needed to improve the evidence base.

Water displacement leg volumetry in clinical studies--a discussion of error sources

Background

Water displacement leg volumetry is a highly reproducible method, allowing the confirmation of efficacy of vasoactive substances. Nevertheless errors of its execution and the selection of unsuitable patients are likely to negatively affect the outcome of clinical studies in chronic venous insufficiency (CVI).

Discussion

Placebo controlled double-blind drug studies in CVI were searched (Cochrane Review 2005, MedLine Search until December 2007) and assessed with regard to efficacy (volume reduction of the leg), patient characteristics, and potential methodological error sources. Almost every second study reported only small drug effects (≤ 30 mL volume reduction). As the most relevant error source the conduct of volumetry was identified. Because the practical use of available equipment varies, volume differences of more than 300 mL - which is a multifold of a potential treatment effect - have been reported between consecutive measurements. Other potential error sources were insufficient patient guidance or difficulties with the transition from the Widmer CVI classification to the CEAP (Clinical Etiological Anatomical Pathophysiological) grading.

Summary

Patients should be properly diagnosed with CVI and selected for stable oedema and further clinical symptoms relevant for the specific study. Centres require a thorough training on the use of the volumeter and on patient guidance. Volumetry should be performed under constant conditions. The reproducibility of short term repeat measurements has to be ensured.

Phlebotonics for venous insufficiency

BACKGROUND

Chronic venous insufficiency (CVI) is a common condition caused by inadequate blood flow through the veins, usually in the lower limbs. It can result in considerable discomfort with symptoms such as pain, itchiness and tiredness in the legs. Sufferers may also experience swelling and ulcers. Phlebotonics are a class of drugs that are often used to treat CVI.

OBJECTIVES

To assess the efficacy of oral or topical phlebotonics.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group trials register (April 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2005), MEDLINE (January 1966 to April 2005), EMBASE (January 1980 to April 2005) and reference lists of articles. We also contacted pharmaceutical companies.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials (RCTs) assessing the efficacy of rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract and aminaftone in CVI patients at any stage of the disease.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. The effects of treatment were estimated by relative risk (RR) or by standardised mean differences (SMD) by applying a random effects statistical model. Sensitivity analyses were also performed.

MAIN RESULTS

Fifty-nine RCTs of oral phlebotonics were included, but only 44 trials involving 4413 participants contained quantifiable data for the efficacy analysis: 23 of rutosides, ten of hidrosmine and diosmine, six of calcium dobesilate, two of centella asiatica, one of french maritime pine bark extract, one of aminaftone and one of grape seed extract. No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Outcomes included oedema, venous ulcers, trophic disorders, subjective symptoms (pain, cramps, restless legs, itching, heaviness, swelling and paraesthesias), global assessment measures and side effects. The results of many variables were heterogeneous. Phlebotonics showed some global benefit (i.e. oedema reduction) (relative risk 0.72, 95% confidence interval 0.65 to 0.81). The benefit for the remaining CVI signs and symptoms must be evaluated by phlebotonic group. There were no quantifiable data on quality of life.

AUTHORS' CONCLUSIONS

There is not enough evidence to globally support the efficacy of phlebotonics for chronic venous insufficiency. There is a suggestion of some efficacy of phlebotonics on oedema but this is of uncertain clinical relevance. Due to the limitations of current evidence, there is a need for further randomised, controlled clinical trials with greater attention paid to methodological quality.

Three treatments for chronic venous insufficiency: escin, hydroxyethylrutoside, and Daflon

Escin, hydroxyethylrutoside (HR), and Daflon have been shown to be safe and effective for the treatment of chronic venous insufficiency (CVI). They seem to work differently than compression therapy, suggesting that they would usefully augment this therapy. All three phlebotonics attenuate the drop in adenosine triphosphate in venous endothelial cells during hypoxia. This attenuates (1) the inflammation response, (2) the attraction of neutrophils, (3) damage to the veins, and (4) the release of growth factors. These factors otherwise would perpetuate venous insufficiency and contribute to varicose veins. Additional independent effects that would be useful for the treatment of CVI are that they reduce permeability and fragility; HR, Daflon, and perhaps escin increase venous tone; escin inhibits hyaluronidase; Daflon and probably HR are attracted to the veins. With regard to similarity, no differences in effect have been established among these phlebotonics.

Chronic venous insufficiency--a well-known disorder with many question marks

Chronic venous insufficiency (CVI) is a common disorder found in many parts of the world. The pathophysiology of this condition is only partly elucidated, and even the development of varicose veins remains unexplained. Microcirculation is greatly affected by CVI, which occasionally induces skin changes and ulcers. Although varicose veins are a common symptom of CVI, they are absent in many patients. Thus, clinical examination is often insufficient for the diagnosis of CVI. Furthermore, the treatment of a common disorder such as CVI is frequently inadequate. The author discusses the overfrequent use of varicose vein surgery, where compression treatment would seem more appropriate and effective, and the current status of compression in the treatment of deep vein incompetence. He recommends that the various manifestations of CVI should be more thoroughly classified. He also examines how sclerotherapy is used to various extents in different countries. Finally he discusses the use of various drugs in the treatment of CVI. It is clear that the pathophysiology and the treatment of CVI must be further examined, in particular to determine whether prevention is possible.

Uptake and localisation of O-(beta-hydroxyethyl)-rutosides in the venous wall, measured by laser scanning microscopy

The uptake and localisation of O-(beta-hydroxyethyl)-rutosides (HR) in the venous wall was studied in 8 patients undergoing crossectomy for a varicose long saphenous vein. The fluorescence of cross-sections of the vein wall was measured by laser scanning microscopy, based on the autofluorescence of HR. Four patients (treated group) received 2 x 1.5 g HR IV before surgery, and four (untreated patients) served as controls. Uptake of HR into the veins from treated patients was seen, with a mean fluorescence intensity of 80.9 units compared to 49.4 units in the untreated veins. The increase in fluorescence was clearly demarcated on the endothelial side of the vein wall. It is concluded that HR passes into the vascular wall, where it is localised in the endothelial and sub-endothelial areas.

Therapeutic effects of hidrosmin on chronic venous insufficiency of the lower limbs

A double-blind, placebo-controlled trial was carried out to assess the effectiveness of a new synthetic bioflavonoid, hidrosmin, in patients with chronic venous insufficiency of the lower limbs. Fifty-seven patients, showing varicose veins and ankle swelling and suffering from local pain and heaviness of the legs, were allocated at random to receive treatment for 45 days with 1 capsule 3-times daily of either 200 mg hidrosmin (30 patients) or placebo (27 patients). Pain and heavy legs were assessed using rating scales; swelling was assessed by a photographic method. The results showed that hidrosmin produced a significant clinical improvement in all of the parameters evaluated; compared with placebo, there was a marked reduction in the main subjective symptoms accompanied by a 10% reduction in swelling. Apart from 1 patient who complained of epigastric pain, there were no reports of adverse events during the study period.

Oxerutins in the prevention of recurrence in chronic venous ulceration: randomized controlled trial

The value of oxerutins [O-(beta-hydroxyethyl)-rutosides] in the prevention of venous ulcer recurrence was investigated in a double-blind randomized controlled trial of 138 patients with recently healed chronic venous ulcers. Oxerutins in the form of Paroven 500 mg twice daily or identical placebo were given, and all patients were provided with elastic compression stockings. At follow-up 3 months later, patients were assessed for re-ulceration and for tablet and stocking compliance. Oxerutins (n = 69) and placebo (n = 69) groups were well matched for age, sex, duration of previous ulceration and deep vein thrombosis. Cumulative re-ulceration by life-table analysis at 12 and 18 months was 22 and 32 per cent respectively for placebo, and 23 and 34 per cent respectively for oxerutins (P = 0.93). Recurrence was more frequent in patients who complied with both tablets and stockings, suggesting that compliance was influenced by continued symptoms (P = 0.006). This trial failed to demonstrate that oxerutins influenced ulcer recurrence.

Time course of the anti-oedematous effect of O-(beta-hydroxyethyl)-rutosides in healthy volunteers

O-(beta-hydroxyethyl)-rutosides (HR) is used for the treatment of disorders of the venous and microcirculatory systems. In order to evaluate the time course of its activity, the effect of HR on a provocation model of orthostatic oedema in healthy volunteers was used. After a 2 week placebo run-in period, 16 healthy volunteers were randomized to HR (2 tablets of 500 mg/day) of placebo for a further 3 weeks, in a double-blind parallel design. Oedema was provoked by standing motionless for 1 h, with measurement of leg volume before and afterwards. The procedure was undertaken at entry to the study and then weekly during the entire 5 week period. There were no significant differences in the extent of oedema produced by the orthostatic challenge during the 2 week run-in period or in the subjects who continued on placebo (approximately 90 arbitrary units i.e. approximately 48 ml). During the 3 week treatment with HR, however, there was a progressive reduction (-1.1, -5.9, and -7.6 arbitrary units after 1, 2, and 3 weeks, respectively) in the volume of induced oedema, which was significant after 2 and 3 weeks of treatment compared to the placebo group.